With the progress of information communication technology, various wireless communication technologies have been developed recently. Among the wireless communication technologies, a wireless local area network (WLAN) refer to a technology allowing surfing the Internet wirelessly using a portable terminal (such as intelligent mobile terminal, tablet computer, portable multimedia player, etc.) at home or in the workplace or in areas providing specific services.
At present, the 802.11 Protocol Group has established a research group of next generation Wi-Fi technology, i.e., high efficiency WLAN (HEW), with the main research tasks of improving the throughput over the existing Wi-Fi technology, improving the effective utilization efficiency of spectrum and improving the quality of experience (QoE). It has carried out much research on clear channel assessment (CCA), e.g., improving the re-utilization rate of space by changing the threshold of CCA, etc.
FIG. 1 shows a principle schematic diagram of a CCA mechanism in the prior art, wherein when station 1 transmits data to station 3, station 2 and the station 1 form an overlapping basis service set (OBSS), and according to the CCA mechanism of the existing Wi-Fi technology, the station 2 must set its CCA busy, and cannot simultaneously transmit data to station 4, so the efficiency of spectrum utilization is low.